Slender annual 1-4 dm, branched above; lvs alternate or scattered or the lowest occasionally in whorls of 2-5, linear, 1-2 cm נ1-2(-3) mm; peduncles 2-8 cm; bracts deciduous; racemes very slender, the whole axis to 10 cm, the floriferous or fructiferous part 1-5 cm, becoming interrupted at base; pedicels 0.5 mm; fls white or greenish-white; wings about equaling the fr. Open woods and fields, especially in sandy soil; Me. to n. N.H., Mich., and Mo., s. to Ga., Ala., and Okla. June-Oct. Wings usually 1.3-1.7 mm; plants from S.C. to se. Va., and from Mo., Ark., and Okla., with wings 2-2.6 mm, have been called P. verticillata var. dolichoptera. (P. verticillata var. a.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
